1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
|
/*
* Copyright (c) 2011, Google Inc.
*/
#ifndef STREAMING_H
#define STREAMING_H 1
#include "object.h"
struct object_database;
struct odb_read_stream;
struct stream_filter;
typedef int (*odb_read_stream_close_fn)(struct odb_read_stream *);
typedef ssize_t (*odb_read_stream_read_fn)(struct odb_read_stream *, char *, size_t);
/*
* A stream that can be used to read an object from the object database without
* loading all of it into memory.
*/
struct odb_read_stream {
odb_read_stream_close_fn close;
odb_read_stream_read_fn read;
enum object_type type;
unsigned long size; /* inflated size of full object */
};
/*
* Create a new object stream for the given object database. An optional filter
* can be used to transform the object's content.
*
* Returns the stream on success, a `NULL` pointer otherwise.
*/
struct odb_read_stream *odb_read_stream_open(struct object_database *odb,
const struct object_id *oid,
struct stream_filter *filter);
/*
* Close the given read stream and release all resources associated with it.
* Returns 0 on success, a negative error code otherwise.
*/
int odb_read_stream_close(struct odb_read_stream *stream);
/*
* Read data from the stream into the buffer. Returns 0 on EOF and the number
* of bytes read on success. Returns a negative error code in case reading from
* the stream fails.
*/
ssize_t odb_read_stream_read(struct odb_read_stream *stream, void *buf, size_t len);
/*
* Look up the object by its ID and write the full contents to the file
* descriptor. The object must be a blob, or the function will fail. When
* provided, the filter is used to transform the blob contents.
*
* `can_seek` should be set to 1 in case the given file descriptor can be
* seek(3p)'d on. This is used to support files with holes in case a
* significant portion of the blob contains NUL bytes.
*
* Returns a negative error code on failure, 0 on success.
*/
int odb_stream_blob_to_fd(struct object_database *odb,
int fd,
const struct object_id *oid,
struct stream_filter *filter,
int can_seek);
#endif /* STREAMING_H */
|
